Surface Density of the Spongy and Palisade Parenchyma Layers of Leaves Extracted From Wideband Ultrasonic Resonance Spectra.

The wide band and air-coupled ultrasonic resonant spectroscopy together with a modified Simulated Annealing metaheuristic algorithm and a 1D layered acoustic-model are used to resolve the structure of plant leaves. In particular, this paper focuses on the extraction of the surface density of the different layers of tissue in leaves having a relatively simple structure. There are three main reasons to select the surface density as the focus of this study: (i) it is a parameter directly extracted by the proposed technique and it requires no further processing, (ii) it is relevant in order to study the dynamic of the water within the different tissues of the leaves and also to study the differential development of the different tissues, and (iii) unlike other parameters provided by this technique (like resonant frequency, impedance, ultrasonic elastic modulus, or ultrasonic damping), this parameter can be easier to understand as it is a direct measure of mass per unit surface. The selection of leaves with a simple structure is justified by the convenience of avoiding an unnecessary complication of the data extraction step. In this work, the technique was applied to determine the surface density of the palisade and spongy parenchyma layers of tissue of Ligustrum lucidum, Vitis vinifera, and Viburnum tinus leaves. The first species was used to study the variation of the surface density at full turgor with the thickness of the leaf, while the two other species were used to study the variation of the surface densities with the variation in the leaf relative water content. Consistency of the results with other conventional measurements (like overall surface density, and cross-section optical and cryo-SEM images) is discussed. The results obtained reveal the potential of this technique; moreover, the technique presents the additional advantage that can be applied in-vivo as it is completely non-invasive, non-destructive, fast, and equipment required is portable.

Emergence of Plasmodium ovale malaria among the French Armed Forces in the Republic of Ivory Coast: 20 years of clinical and biological experience.

BACKGROUND: French military surveillance identified an increase in Plasmodium ovale attacks among soldiers in Ivory Coast. This emergence and the low sensitivity of biological tests raise the question of a possible role of P. ovale variant species. METHODS: Epidemiological data about P. ovale attacks from 1993 to 2012 were studied; the species diagnosis was based on a thin blood smear and/or a quick diagnostic test. Clinical and biological features in soldiers hospitalized in 2 French military hospitals were also reviewed. Malaria polymerase chain reaction followed by genotyping was performed when available. RESULTS: French military physicians declared 328 P. ovale attacks over the 20-year study. A peak of incidence occurred in 2005. Among patients with positive blood smears, the quick diagnostic test was positive in 33 of 101 tests performed. The hospital study showed that symptoms and biological changes were not specific, which made diagnosis challenging: fever, anemia, and thrombocytopenia were not present in 20%, 71%, and 23% of the 45 confirmed cases, respectively. It was possible to perform molecular investigations on 19 clinical isolates: 18 were classic haplotypes with additional polymorphism and 1 was variant. CONCLUSIONS: This emergence of P. ovale malaria enabled a good description to be made in nonimmune patients. The lack of sensitivity of both clinical features and quick diagnostic tests suggests an underestimation. Reasons for this outbreak are especially intense exposure to the vectors and the insufficient efficacy of doxycycline against P. ovale. The polymorphism of classic haplotypes of P. ovale rather than variant forms could be involved.

[Comparison of the mycobacteria growth indicator tube with solid culture for the detection of tuberculosis complex mycobacteria from blood]. / Comparaison du milieu mycobacteria growth indicator tube et des milieux solides pour l'isolement des mycobactéries du complexe tuberculosis à partir d'hémocultures.

AIM OF THIS STUDY: The aim of this study was to compare the mycobacteria growth indicator tube and solid culture for recovery of complex tuberculosis mycobacteria from blood. PATIENTS AND METHODS: One hundred and twenty-five specimens from 67 Djiboutian patients with a positive serologic diagnosis of HIV and fever were collected in an Isolator tube. After centrifugation and washing with phosphate-buffer, smears were prepared from the pellet for auramin staining. The remaining sediment was suspended in 1 ml of buffer. One half was inoculated into two MGIT (incubation at 30 and 37 degrees C into Bactec 960) and the other onto two Loewenstein-Jensen and two Coletsos medium (incubation at 30 and 37 degrees C). RESULTS: Eight cultures were contaminated: three on solid medium and MGIT simultaneously, five in MGIT only (three coagulase negative staphylococci, five enterobacteria). Fourteen strains of M. tuberculosis (six patients) and three M. canettii (two patients) (12 on solid media and MGIT, five in MGIT only) were recovered. The mean time to detection was 32.8 days for solid medium and 20.4 days for MGIT. Of a total of 25 patients with culture-proven tuberculosis, two patients had a positive blood culture only, six had blood and other specimens positive culture, 17 had a non blood specimens positive culture only. CONCLUSION: MGIT processed into Bactec 960 is a viable tool for the detection of complexe tuberculosis mycobacteria from blood and the high-frequency of these mycobacteremia in HIV infected patients from country where the prevalence of tuberculosis is high is confirmed. However, the cost/benefit ratio of this bacteriologic diagnosis had to be evaluated in developping country.

[Risk of nosocomial infection in Intertropical Africa. Part 4: prevention]. / Le risque nosocomial en Afrique Intertropicale. Partie 4: prévention.

Nosocomial infections have long been neglected in Sub-Saharan Africa, even though their prevalence is higher than in developed countries. Recently, however, this major public health problem has been the focus of a growing number of recommendations not only from the World Health Organization but also from some national health ministries. Because of the numerous limitations especially in financial resources in these regions, priority must be given to the implementation of simple and cost-effective measures. Accordingly the greatest efforts must be devoted to educating healthcare workers and patients about the importance of handwashing, eliminating unnecessary injections and transfusions, performing the latter acts in aseptic conditions, isolating patients with communicable diseases, handling waste products safely, and using antimicrobials properly. Amid the daunting health issues facing Sub-Saharan Africa, implementing these inexpensive measures that could save the lives of thousands of patients and healthcare workers appears easy. However it will require a cultural revolution. The keys to success will be changing the organizational culture, developing a commitment to prevention and evaluating performance regularly.

Le risque nosocomial en Afrique intertropicale - Partie 4 : prevention

Alors que les infections nosocomiales representent en Afrique Intertropicale un probleme de sante publique encore plus preoccupant que dans les regions developpees du globe; leur prevention est longtemps restee negligee. Depuis quelques annees neanmoins elle fait l'objet d'un nombre croissant de recommandations emanant d'instances internationales comme l'Organisation Mondiale de la Sante ou d'un certain nombre de ministeres concernes. Les multiples contraintes du sous-continent; notamment economiques; imposent la mise en place prioritaire de mesures simples et adaptees. Les efforts doivent ainsi porter sur l'education des personnels de sante mais aussi des patients; le lavage des mains; la limitation des injections et des transfusions et leur realisation dans des conditions securisees; les mesures d'isolement; la gestion des dechets ou encore les bonnes pratiques d'antibiotherapie. Cette revolution culturelle; semblant decalee face aux grandes urgences africaines; pourrait neanmoins epargner a peu de frais la vie demilliers de patients et soignants. La culture d'etablissement; la priorisation et l'evaluation reguliere des mesures sont des points-cles du succes

[Diagnosis of imported malaria in France]. / Diagnostic du paludisme d'importation en France.

The need for diagnosis of imported malaria is frequent in France. Diagnosis biological tools are different, according methods, sensitivity, interpretation and costs. Strategies for their use could be stratified according locally available methods, and experience of the practician.

[Risk of nosocomial infection in intertropical Africa--part 3: health care workers]. / Le risque nosocomial en Afrique intertropicale. Partie 3: les infections des soignants.

Parts of the nosocomial infections issue are the professionally-acquired infections of health care workers. This problem is widely neglected in sub-Saharan Africa, and little is known on the subject, in spite of the high prevalence of blood-borne infections such as HIV or hepatitis B and C, and air-borne diseases like tuberculosis. Besides, unsafe practices and accidents like blood exposures are more frequent than in western countries. This is due to the lack of political concern, of safer equipment and of specific teachings. Most of this severe infections' treatments are long, difficult or unavailable in Subsaharan Africa. The loss of contaminated health care workers can then become devastating for their family and the fragile health care structures of those developing countries. Finally, one should not underestimate the risk of infection transmission from health care provider to patient, like in several past outbreaks of Ebola hemorrhagic fever.

[Risk of nosocomial infection in intertropical Africa--part 2: patient infection]. / Le risque nosocomial en Afrique intertropicale partie 2: les infections des patients.

Patients admitted to hospitals in tropical Africa are at increased risk for nosocomial infection. However accurate description of this risk is difficult due to a lack of published data in the literature. The main promoting factors are poor health care facilities, high microbial levels in the hospital and community environment and generally uncertain health status. Most available information is about neonatal infection. The increasing number of reports involving multiresistant bacteria is evidence of poor hospital sanitation. Infections involving operative incision sites, tuberculosis and respiratory virus transmission are grossly underestimated. Infections transmitted by the parenteral route are probably decreasing due to more widespread use of disposal equipment and adequate transfusion safety measures. Epidemics involving viral hemorrhagic fever are rare but highly publicized events that attest to daily neglect of nosocomial risk factors in some health care facilities

Therapeutic treatment with poly(ADP-ribose) polymerase inhibitors attenuates the severity of acute pancreatitis and associated liver and lung injury.

BACKGROUND AND PURPOSE: The mortality associated with acute pancreatitis (AP) is largely attributable to abnormalities that occur in distant organs and supportive care remains the only treatment for patients with these complications. Recently, prophylactic pharmacological blockade of poly(ADP-ribose) polymerase (PARP) enzymes has been shown to attenuate the severity of the disease. However, the clinical relevance of PARP inhibitors administered after the onset of AP remains uncertain. The aim of the present study was to investigate the therapeutic effects of PARP inhibitors in established AP. EXPERIMENTAL APPROACH: Mice were fed a choline/methionine-deficient/ethionine-supplemented (CMDE) diet to induce AP. PARP inhibitors were given at 36 h after the onset of CMDE diet. Severity of pancreatitis was assessed by measurements of serum amylase, lipase, IL-1beta and IL-6, and histological grading. Serum hepatic enzymes, myeloperoxidase (MPO) activity and morphological changes were measured as indicators of hepatic insult. Lung injury was evaluated by MPO activity and morphological changes. Survival rates of mice were monitored for 7 days. KEY RESULTS: CMDE diet administration resulted in a significant increase in serum amylase, lipase, IL-1beta, IL-6, alanine aminotransferase and aspartate aminotranferase levels, indicating AP and associated liver injury. Analysis of the histopathological changes in pancreas, liver and lung revealed extensive tissue damage. Treatment of mice with PARP-inhibitors after the onset of AP was associated with a reduction in the severity of AP and, accordingly, with a reduced mortality rate. CONCLUSIONS AND IMPLICATIONS: Our results support the therapeutic application of PARP inhibitors in the treatment of established AP.

Le risque nosocomial en Afrique intertropicale. Partie 3 : les infections des soignants

La grippe est une maladie virale saisonniere qui peut etre benigne ou redoutable du fait du taux de morbidite et de mortalite occasionne lors des epidemies. En absence de donnees epidemiologiques et virologiques en Cote d'Ivoire; un reseau de surveillance de la grippe a ete mis en place a Abidjan pour determiner le niveau de circulation de virus grippaux et caracteriser les virus isoles. De janvier 2003 a decembre 2004; soit pendant 24 mois; des secretions nasales ont ete collectees dans les formations sanitaires de la ville d'Abidjan. L'identification des virus grippaux au laboratoire a ete realisee par technique ELISA utilisant des anticorpsmonoclonaux anti-A et anti-B (immunocapture) et par isolement sur cellules MDCK. Une partie des echantillons d'origine et les isolats ont ete envoyes pour confirmation a l'Institut Pasteur de Paris (2003) et au National Institute for Communicable Diseases (NICD) a Johannesburg. Parmi les 211 echantillons analyses; 30 (12;8) se sont reveles positifs : 22 isolats de virus InfluenzaA dont 21 de typeA(H3N2) et une souche de typeA(H1N1); et 8 isolats de virus Influenza B. Ces souches ont ete isolees majoritairement chez des patients de 0-5 ans (34) et 15-59 ans (47). Bien que plus de 60des souches aient ete isolees en juin et en octobre; il est difficile de definir une saisonnalite du fait de la courte duree de l'etude. La poursuite de cette etude permettra une meilleure appreciation de la saisonnalite; des caracteristiques virologiques et cliniques pour envisager une prevention par la vaccination

[Risk of noscomial infection in intertropical Africa--part 1: background]. / Le risque nosocomial en Afrique intertropicale--partie 1: le contexte.

Nosocomial infection is a risk in any health care setting. A review of recent medical literature shows that there is a paucity of information on nosocomial infection in intertropical Africa. Often misunderstood or denied, nosocomial infection is in reality an underestimated public health problem at most medical facilities even university hospital centers. However most hospitals are confronted with the same financial, structural and logistics difficulties, with limited training and awareness about hospital hygiene among caregivers, and with situations bringing together contagious infections with susceptible subjects. Assessment of the risks for patients and caregivers is a necessary prerequisite for implementing measures to control nosocomial infections in intertropical Africa.

[Rapid immunochromatographic tests for detection of malaria: principles and strategies for use]. / Tests immunochromatographiques rapides de détection du paludisme, principes et stratégies d'utilisation.

Malaria is a parasitological emergency requiring safe quick accurate diagnosis so that appropriate therapy can be implemented. A number of rapid diagnostic tests based on detection of HRP2 Ag, enzymes, LDH or aldolase are now available. However the use of these tests is restricted to trained, experienced staff in special situations. The purpose of this report is to describe the different tests on the market and clarify the limitations for their use.

[Achievement quality evaluation of pretransfusion bedside test]. / Evaluation de la qualité de réalisation des tests de concordance ultime au lit du patient.

As far as transfusions accidents are concerned, immunological causes are frequent. Pretransfusion Bedside Compatibility Tests (PBCT) are the last chance to avoid them. However low data are disponible on the quality their realisation is achieved. The aim of the study is to evaluate the quality level of achievement of these tests, in HIA Laveran Hospital (Marseille Armees, France). During 13 months, from november 2001 to december 2002, we systematically analysed PBCT after use (analysis rate 91%). Three kinds of errors have been noticed: Technical errors, understanding errors and both. Overall mistake rate was 10.4% (1632 tests analysed). In the same time, a complementary formation was dispensed to users responsible of misfits. This formation was successful, decreasing the overall mistake rate from 22.8% (november 2001) to 10.7% (december 2002). This study is an evidence of the importance to evaluate achievement quality of PBCT and shows how efficient can be simple correction methods.

[American pulmonary histoplasmosis. Prospective study with 232 soldiers after a 2-year assignment in Guiana]. / Histoplasmose pulmonaire americaine. Etude prospective chez 232 militaires ayant effectue un sejour de 2 ans en Guyane.

The purpose of this report is to describe the results of a prospective study on pulmonary histoplasmosis in French Guiana. Chest radiographs were performed in 232 French legionnaires returning from a two-year assignment in French Guiana. Further examinations were performed in a total of 8 subjects in whom chest radiographs demonstrated the presence of nodules in the lungs. No evidence of cancer or tuberculosis was found. Findings confirmed histoplasmomas in two cases and demonstrated probable histoplasmosis nodules in 6 cases including three involving calcified lesions. Five of these eight patients had been in high-risk rain forest environments. Pulmonary histoplasmosis should be considered as a possible diagnosis in subjects returning from endemic zones. Confirmation depends on a spectrum of findings. Calcified nodules require only radiographic surveillance with follow-up at six months. Non-calcified nodules require further investigation including CT-scan, bronchoscopy, and serological tests. Surgical biopsy may be necessary to achieve exact histological and mycological identification of the lesion and is recommended in smokers.

[Suspected epidemic at a hospital in Senegal]. / Suspicion d'épidémie dans un hopital Sénégalais.

Most outbreaks of noscomial infection are detected by means of molecular biological testing. However Euclidian distance is a rapid, reliable alternative if facilities for molecular biological testing are unavailable, as at the Principal Hospital in Dakar, Senegal. Over the 7 month period from 01/10/98 to 31/04/99, 110 of the 1033 blood cultures specimens collected in a group of 2360 children hospitalized in pediatric departments A and B of the Principal Hospital were found to be positive for Burkholderia cepacia. This high incidence suggested the possibility of an epidemic. This likelihood was further increased by evidence showing that all strains exhibited the same biotype and by results of pulsed-field electrophoresis (CHEF Mapper, Spel digestion) indicating that bacteria was of clonal origin. These findings were entirely consistent with those obtained by Euclidian distance but excessive mortality was not observed in the children involved. Testing of environmental specimens demonstrated the presence of the same strains in respirators and catheters. The most feasible hypothesis to account for these findings is environmental contamination resulting in mucocutaneous contamination of patients. Hemoculture containers were probably contaminated during handling.

[Evaluation of the OptiMal test in the diagnosis of imported malarial outbreak]. / Evaluation du test OptiMal dans le diagnostic des accès palustres d'importation.

The OptiMal test is an immuno-chromatographic dipstick test that permits indiscriminate detection of Plasmodium falciparum and other species of human malaria. The purpose of this study was to evaluate the efficacy of the test for diagnosis of imported malaria. A total of 244 patients with a presumptive diagnosis of imported malaria in France were included during the study period. The reference test, i.e., combined thick and thin blood films, demonstrated infection by Plasmodium falciparum in 58 cases, Plasmodium vivax in 12, P. ovale in 8 and Plasmodium malariae in 2. The OptiMal test detected only 46 of the 55 Plasmodium falciparum cases. The sensitivity of the test for diagnosis of that species was 80%, its specificity was 98%, and its positive and negative predictive values were 95 and 93% respectively. Parsitemia studies showed poor test reliability for densities lower than 150/ul. Detection of other species was accurate in 21 out of 22. The results of this study demonstrate that the current version of the OptiMal test should be used with great caution for the diagnosis of malarial infection in hospital practice.

Rickettsia africae, a tick-borne pathogen in travelers to sub-Saharan Africa.

BACKGROUND: African tick-bite fever occurs after contact with ticks that carry Rickettsia africae and that parasitize cattle and game. Sporadic reports suggest that this infection has specific clinical and epidemiologic features. METHODS: We studied patients who were tested for a rickettsial disease after returning from a visit to Africa or Guadeloupe. To assess the value of the microimmunofluorescence assay, Western blotting, and cross-adsorption assays, we compared the results of these tests in 39 patients in whom African tick-bite fever had been confirmed by the polymerase-chain reaction assay, cell culture, or both; 50 patients with documented R. conorii infection; and 50 blood donors. These diagnostic criteria were then applied to 376 additional patients who had returned from southern Africa and 2 who had returned from Guadeloupe and whose serum was being tested for rickettsial disease. RESULTS: In the 39 patients with direct evidence of R. africae infection, the combination of microimmunofluorescence assay, Western blotting, and cross-adsorption assays showing antibodies specific for R. africae had a sensitivity of 0.56; however, each test had a positive predictive value and a specificity of 1.0. An additional 80 patients were found to have an R. africae infection on the basis of these serologic criteria. Infections with R. africae were acquired by visitors to 11 African countries and Guadeloupe. The illness was generally mild and was characterized by a rash in 46 percent of the patients; the rash was usually maculopapular or vesicular and rarely purpuric. Ninety-five percent of patients had an inoculation eschar or eschars, and 54 percent of these patients had multiple eschars, a finding that is unusual in patients with rickettsial infection. CONCLUSIONS: In this series, R. africae was the cause of nearly all cases of tick-bite rickettsiosis in patients who became ill after a trip to sub-Saharan Africa.

Evidence for recombination in natural populations of dengue virus type 1 based on the analysis of complete genome sequences.

Recombination events are known to occur in non-segmented RNA viruses like polioviruses or alphaviruses. Analysis of the subgenomic sequences of dengue virus type 1 (DENV-1) structural genes has recently allowed the identification of possible recombination breakpoints. Because DENV is a major human pathogen, this discovery might have important implications for virus pathogenicity, vaccine safety and efficiency, or diagnosis and, therefore, requires clear confirmation. We report the complete sequence determination of one Asian and two African strains of DENV-1 isolated from human patients. Rigorous sequence analysis provided strong evidence for the occurrence of intragenomic recombination events between DENV-1 strains belonging to different lineages. Singapore S275/90 strain appears to be the evolutionary product of a recombination event between viruses belonging to two distinct lineages: one lineage includes an African strain isolated in Abidjan (Ivory Coast) and the other includes isolates from Djibouti and Cambodia. The 'Recombination Detection Program', bootscanning and analysis of diversity plots provided congruent results concerning the existence of a two-switch recombination event and the localization of recombination breakpoints. Thus, the 5' and 3' genomic ends of the Singapore S275/90 strain were inherited from a Djibouti/Cambodia lineage ancestor and an internal fragment located in the envelope/NS1 region originated from an Abidjan lineage ancestor.